1. Field of the Invention
The present invention relates generally to a door shelf of a refrigerator, and more particularly, to a device to lock a cover hinged to a main body of the door shelf in such a way as to selectively open the main body.
2. Description of the Prior Art
As well known to those skilled in the art, a refrigerator is an appliance intended to store various kinds of food for a lengthy period of time by a refrigerating cycle using a refrigerant. Generally, the refrigerator has a freezer compartment and a refrigerator compartment. The freezer compartment is used to freeze and store food, which has to be preserved for a lengthy period of time. On the other hand, the refrigerator compartment is used to store food for a short period of time without freezing the food, and is used to maintain the freshness of the food while preventing the food from spoiling. Typically, the freezer compartment is placed on the upper portion of the refrigerator while the refrigerator compartment is placed on the lower portion thereof. However, recently there has been proposed a large-capacity refrigerator which is designed to provide on its left side a freezer compartment and on its right side a refrigerator compartment. Further, such a large-capacity refrigerator is provided on its storage door a home bar-type shelf door to open and close a door shelf without opening and closing the storage door, thus reducing the waste of electricity caused by the escape of cold air from the refrigerator compartment due to frequent opening of the storage door. A conventional refrigerator will now be described with reference to FIGS. 1 to 3.
FIG. 1 is a front view of a conventional refrigerator which is now widely used. The refrigerator 100 is provided on its right side with a refrigerator compartment. A storage door 101 is provided at the refrigerator compartment to selectively open the refrigerator compartment. A freezer compartment 102 is provided on the left side of the refrigerator 100, and has a freezer door 102 to selectively open the freezer compartment 102. A water dispenser 104 and an ice dispenser 103 are provided on the outer wall of the freezer door 102 to supply cool water and ice to the user. The storage door 101 of the refrigerator 100 has a recessed portion to define a chamber. In this case, the chamber communicates with a door shelf. A shelf door 105 is provided on the outer wall of the storage door 101 to allow a user outside the refrigerator 100 to access the chamber. The door shelf will be described in detail with reference to FIGS. 2 and 3.
FIG. 2 shows a door shelf 200 mounted to the storage door 101 inside of the refrigerator 100. The chamber is defined by the storage door 101 and the door shelf 200. As described above, the chamber may be opened and closed by the shelf door 105 provided on the outer wall of the storage door 101 from the outside of the refrigerator 100. In addition, the chamber may be opened or closed by a cover 202 from the inside wall of the storage door 101. The chamber stores beverages or potable water which is frequently drunk. In this case, it is possible to easily access the beverages stored in the chamber through the shelf door 105, thus minimizing the loss of electricity caused by the escape of cool air from the refrigerator compartment. The cover 202, hinged to a main body 201 of the door shelf 200, is provided on the inside wall of the storage door 101 to open the chamber from the inside wall of the storage door 101, thus allowing a user to replenish the chamber with beverages. As shown in FIG. 3, in order to lock the cover 202 to the main body 201 when the cover 202 is closed, the cover 202 and the main body 201 are provided with a device to lock the cover while allowing the cover to be selectively opened. Generally, there has been proposed a conventional device to lock a cover using hook units 301a and 301b. 
However, the conventional device to lock the cover of the refrigerator's door shelf has a problem in that it makes a big noise, due to the hook units, when closing the cover. The conventional device has another problem in that the cover may be damaged according to the intensity of a force applied thereto when closing the cover, because the main body comes into direct contact with the cover. The conventional device has a further problem in that the cover is not completely closed but may be instantaneously and resiliently opened due to impact energy generated when closing the cover. Furthermore, the conventional device has a still further problem in that the cover is not completely locked to the main body, but is slightly spaced from the main body in the case where the force to close the cover is weak, so that the cover may undesirably swing when opening and closing the storage door.